With the advent of increased access to computers, home entertainment systems, and networks such as the Internet and the World Wide Web (WWW), it has become increasingly common for a wide variety of providers to present to multiple users content on demand. Such content includes but is not limited to streaming video, audio and/or data. Such content is also increasingly common to shared receiving systems serving multiple living units such as hotels and the like. Video on Demand (VOD) is a streaming content service enabling a user to obtain video information immediately in real time through a request terminal. This is contrasted with pay per view, where the user must abide by the schedule of a program provider.
In a typical streaming application such as video on demand, each user has the opportunity to view any particular content starting at random times. Each user gets a complete download of the content they have selected. Each user receives streaming content on a channel which is typically dedicated solely to the content the particular user is viewing. In systems with many potential viewers, many channels and a large amount of bandwidth are required. As the amount of required bandwidth increases, costs associated with providing the bandwidth increase as well. Practical limits on bandwidth result in a limited amount of bandwidth availability for multiple channels.
When bandwidth is limited, especially in broadcast media, the number of users able to share the bandwidth is limited to the number of unique channels allocated to the system. Even if multiple users want to access the same content, a unique download is required since there is little probability that two users will start the same content at the same time.